Latch hold back feature for door locks



t 1957 E. SCHLAGE 25808279 LATCH HOLD BACK FEATURE; FOR DOOR LOCKS Filed June 9, 1955 2 Sheets-Sheet 1 7 i p16 3 ///V// I j 15 2 l2 5 I Zn FIG 3 T I I I I V 17 A/ 26 2 K 45 4 INVENTOR. sum-:51 L. SCHLAGE (8 18 11, 170 3111 v wood Oct. 1, 1957 E. L. SCHLAGE 2,808,279

LATCH HOLD BACK FEATURE FOR DOOR LOCKS med June 9, 1955 2 Sheets-Sheet 2 v VENTOR. ERNES SCHLAGE BY 60 wymmwma iinited States PatentlQ LATCH HGLD BACK FEATURE FOR noon LOCKS Ernest L. Schlage, Eurlingame, Calif., assignor to Schlage Lock Company, a corporation Application June 9, 1955, Serial No. 514,140

3 Claims. (Cl. 292169) This invention relates to doorlocks and especially that type in which assembly or removal of the lock from a door is controlled by overdepression or retraction of the latch bolt.

In Patent No. 2,207,877, a door lock is shown in which the latch bolt may assume any one of three dilferent positions, to wit: an extended position, a retracted position and an overretracted position. A spring actuated latch en ages the latch bolt when it assumes retracted position and normally prevents overretraction; however, a special tool may be inserted to release the latch so as to permit overretraction, overdepression or retraction being then accomplished by exerting thumb pressure and pushing the latch bolt inwardly and maintaining thumb pressure as long as the latch bolt assumes the overdepressed position. Overretraction of the latch bolt is only resorted to during removal or installation of a door lock, as overretraction of the latch bolt releases a dogging mechanism which secures the spindles against removal after installation and conversely releases the spindles during removal of the lock.

The object of the present invention is to provide a door lock in which assembly or removal of the lock from a door is controlled by overretraction or depression of the latch bolt, and especially to provide a spring actuated latch whereby the latch bolt may be temporarily retained in its overretracted position, and which will also function as a stop member to prevent overretraction of the latch bolt during normal operation of the lock.

The lock mechanism generally stated comprises a housing, a retractor and a connected latch bolt slidably mounted therein, a single or divided spindle whereby the retractor and latch bolt is retracted, a main spring whereby the retractor and latch bolt is normally maintained in projected position, a dogging mechanism engaging and securing the spindle or spindles against removal, and finally a spring actuated latch which normally prevents overretraction of the latch bolt, but which may be released to permit overretraction and when released functions to releasably secure the latch bolt in the overretracted position.

The invention is shown by way of illustration in the accompanying drawings, in which:

Fig. l is a longitudinal horizontal section of the door lock showing it mounted in a door, and also showing the latch bolt in its overretracted position;

Fig. 2 is a similar section showing the latch bolt in the normal retracted position;

Fig. 3 is a similar section showing the latch bolt in the normal projected position;

Fig. 4 is a vertical longitudinal section showing the lock installed in the door;

Fig. 5 is a perspective view of the latch bolt and the guide member to which it is secured;

Fig. 6 is a perspective view of the forward end of onehalf of a housing section;

Fig. 7 is a perspective view of the bearing plate;

2,808,279. Patented Oct. 1, 1957 Fig. 8 is a perspective view of the retractor; and,

Fig. 9 is a perspective view of one of the spindles.

Referring to the drawings in detail and particularly Figs. 1 to 4, A indicates a portion of a door in which'is drilled or bored two holes, one through the edge of the door as indicated at B and the other transversely of the door as indicated at C. The lock housing half of which is indicated at. 2 in Fig. 6 is inserted through the hole B and its inward movement is limited by a faceplate 3 which is secured in place by screws 4 (Fig. 1). In the outer end of the housing and normally projecting through the faceplate is a latch bolt 5 which is secured to a slidably mounted latch bolt guiding member 6. This guide is U-shaped, see Fig. 5, and straddles a stationary plate 7 disposed crosswise of the housing, this plate together with the housing forming a support and guide for the latch bolt guiding member. A main spring 8 is interposed between the plate 7 and the outer end 6a of the guide member (Figs. 1-3), this spring serving to normally maintain the latch bolt in projected position.

Adjacent the inner end of the housing is slidably mounted a retractor, said Fig. 8. The retractor is also U-shaped and consists of two spaced apart side sections 99 and a connecting end section 10. The side sections each have an opening formed therein, the forward portion of each opening being rounded as at lliia and the rear portion of each opening presenting a straight vertical face 11, which is acted upon by the rollback members of the spindles as will hereinafter be described. The portions of the side sections of the retractor behind the vertical faces 11 will hereinafter be referred to as detents 12 as they interlock with the respective spindles to secure them against removal at all times, except when the latch bolt is overdepressed for the purpose of releasing the spindles during assembly or removal of the lock from the door.

The lock structure here described shows two spindles, but a single spindle or a telescoping type of divided spindle such as shown in Patent No. 2,207,877 may be employed. The spindles here illustrated are of the tubular type, see Fig. 9, and are indicated by the numeral 16. The inner end of each spindle is cut away as indicated at 13 to form a pair of shoulders l4l4 which limit rotation of the spindles, and outwardly, but adjacent the shoulders, are formed slots 15 which are provided for reception of the interlocking detents 12 previously referred to, and to form rollback members 15a which engage the vertical faces 11 of the retractor. The outer ends of the spindles are provided with knobs not shown which may be secured thereon in any suitable manner.

' With the spindles in place, see Figs. 2, 3, the detents 12 enter the slots 15 of the respective spindles and as such interlock with the spindles and secure the spindles against endwise removal. If a spindle is rotated in the direction of arrow a, see Fig. 4, a rollback member 15:: will engage tthevertical face '11 of the retractor and force it rearwardly to a position where the latch bolt assumes normal retracted position, see Fig. 2. Over-depression of the latch bolt inwardly of the position of Fig. 2 is prevented by a stop element 18 (Figs. 2, 6) formed on the lock housing 2. This stop element 18 is engaged by the free end of a latch element 17 carried by latch bolt guiding member 6 as best seen in Figs. 1-3. Latch 17 comprises an elongated strip bent so as to be received at one end within the outer end 6a of the latch bolt guiding member 6 and interposed between said outer end 6a and spring 8. In order to overdepress the latch 5 inwardly of the position of Fig. 2, it is apparent that'the latch 17 must be moved out of abutment with stop 18. This is accomplished by inserting a special tool in the form of a wire rod/such as shown at 19. This when inserted engages the latch 17 and releases it with relation to the stop 18,

then by applying manual pressure the latch bolt may be overdepressed and the special tool removed. It should be noted that an opening or slot 20, see Fig. 4, is formed in the innerend of the latch ar-m'17, and that the stop 18 in the form of a lug which projects from the side wall of the housing, see Fig. 6, enters the slot whenthe latch bolt is .ovterdepressed, and thus engages the latch and .releasably secures the latch bolt in the overdepressed position, see Fig. l.

The retention of the latch bolt in this position is impontant; for instance, when removing a door lock for inspection, repair, 101 otherwise, the mechanic or locksmith doing the work naturally can work quicker and better if both hands are used, and they both can be used if the latch bolt is releasably retained in this position. If no means is provided for temporarily retaining the latch bolt in its 'overdepresscd position, the mechanic doing the work will have to use one hand to hold the latch bolt in the overdepressed position and thus has only one hand to work with while inserting or removing the spindles, etc. Another reason for releasably securing the latch bolt in its overdepressed position, is that it very materially simplifies installation and written instructions for installation, as the latch bolt can be overdepressed and secured in that position before leaving the factory. When shipped in that condition and when the lock finally reaches the carpenter or mechanic who will install the lock, all he has to do, is to insert the latch bolt in the hole B ofv the door and secure it in place by means of the screws 4. Both hands are free to insert and drive the screws into the door and both hands remain free while installing the spindles and escutcheons, plates, etc. After installation is completed he merely inserts the tool 19 and releases the latch -17 with relation to the stop or lug 18 and when so released spring 8 returns the latch bolt to normal proj'ected position and by then removing the special tool, the lock is ready for use.

By referring to Fig. 4 it will be noted that the rollback member 15a of one of the spindles is in engagement with the vertical face 11 of .the retractor. In this position the detentlZ formed behind the vertical face 11 has fully entered the slot 15 of the spindle and thereby secures the spindle against endwise removal. During rotation of the spindle the rollback member engages the vertical face 11 of the retractor and forces it rearwardly, and as the retractor moves rearwardly the latch bolt is retracted as it is connected with the retractor by means of a motion multiplying lever 25. Rotation of the spindle or spindles is limited as previously stated by one or another of the shoulders l414 formed on the inner end of each :spindle as one or another of the shoulders will engage a stop 26 formed on the bearing plate 27, see Fig. 7. The rotation of the spindles may, for instance, be limited to .a quarter of a revolution by the stop 26, but due to the use of the motion multiplying lever 25 the latch bolt will be fully retracted to the position shown in Fig. 2. It is essential that the detents are not fully retracted from the :slots 15 during normal retraction of the latch bolt. It is only when the latch bolt is overdepressed or retracted that the detents are fully retracted with relation to the slots 15,

and when so retracted the vertical faces 11 of the retractor will assume the position shown in Fig. 1, thus permitting free insertion or removal of the spindles.

The housing enclosing the latch bolt and the retracting mechanism actuating the latch bolt is divided into two halves to facilitate assembly of the mechanism. The bearing plate 27, see Fig. 7, which carries the stop 26 is clamped and secured between the two halves of the housing at a point in alignment with the spindles. The plate has a bearing boss 28 on each side to rotatably receive and support the inner ends of the spindles, and it has a forwardly projecting arm 29 which supports one end of the motion multiplying lever 25. The bearing plate is here only briefly referred to, as it is fully described and forms a part of my copending application entitled Bearing and Spindle Structure for Door Locks, filed May 18, 1954, Serial No. 430,697. The spring arm or latch 17 is carried by the latch bolt and its guide member 6 as clearly shown in Figs. 1 to 3, and while the stop lug 18 is shown in Fig. 6 as forming an integral part of the housing, it may obviously be riveted or otherwise secured thereto.

lclaim: l. in a latch bolt unit of the character described, a

housing, a latch bolt in the housing, said latch bolt adapted to assume a projected, a retracted and an overretracted position, means normally maintaining the latch bolt in the projected position, a lug in the housing, and a latch arm carried by the latch bolt, said latch arm adapted to engage the log to retain the latch bolt in the overretracted position, said latch arm being manually releasable to permit the latch bolt to return to projected position.

2. In a latch bolt unit of the character described, a housing, a latch bolt in the housing, said latch bolt adapted to assume .a projected, a retracted and an overretracted position, means normally maintaining the latch bolt the projected position, a lug in the housing, and a latch arm carried by the latch bolt, said latch arm engaging the lug when the latch bolt is retracted, said engagement normally preventing overret-raction of the latch bolt, said latch arm being manually releasable with relation to the log to permit overretraction of the latch bolt, and other means .on the latch arm for engaging the lug to releasably retain the latch bolt in the overretracted position.

3. In a latch bolt unit of the character described, a housing-a latch bolt in the housing, said latch bolt adapted to assume a projected, a retracted, and an overretracted position, uneans normally maintaining said latch bolt in said projected position, a lug and a latch ann separately carried by said latch bolt and said housing, said latch arm adapted to engage said lug to retain said latch bolt in said overmetracted position, said latch arm being manually releasable to permit said latch bolt to return to said projected position.

7 References Cited in the file of this patent UNITED STATES PATENTS 2,207,877 'Schlage July 16, 1940 

